Potentiation of CFTR Gating by an Energetically Additive Mechanism

Abstract

significant effect of the toxin is found, possibly related to decreased lipid mobility [4]. Here we will provide an overview of membrane texture in a range of systems and describe our efforts to understand and systematize the observations.[1] JACS (2009). Giant plasma membrane vesicles (GPMVs) isolated from mammalian cell lines contain coexisting liquid phases at low temperature, a single liquid phase at elevated temperatures, and undergo robust micron-sized critical fluctuations near the miscibility transition which is typically close to room temperature. In past work, we have measured the temperature dependence of critical composition fluctuations and speculated that mammalian cells tune their membrane composition to maintain a room temperature critical point in order to experience <100nm super-critical composition fluctuations under growth conditions of 37 C [1]. Here, we present evidence that cells actively tune membrane critical temperatures (Tc) to a specific temperature difference below growth temperatures by preparing GPMVs from ZF4 cells, a zebrafish cell line that is capable of growing at temperatures ranging between 20 and 32 C. As was the case in mammalian cell lines, ZF4 cells produce GPMVs with coexisting liquid phases at low temperature and micron-sized critical fluctuations near the miscibility transition. ZF4 derived GPMVs transition temperatures shift to lower values when cells are grown at lower temperature,